The developers at Irrational also stressed that due to Columbia's wide-open spaces, BioShock Infinite is not a "corridor shooter" like the previous BioShock games. The environment opens up more and more as you progress through the game, and after a few hours the levels become rather enormous, with enemies scattered around on multiple rooftops and platforms.
Thankfully, there's a very important tool that helps you get around these spaces: the Skylines. If you've seen any footage from Infinite, then you must have seen the Skylines. They span the gaps between Columbia's floating neighborhoods, and though they're meant for sky trams, you'll traverse them using an arm-mounted tool with three spinning hooks on it. And yes, you can hit people with it. But more importantly, traversing the Skylines—despite how impressive it looks—is simple, and the controls become intuitive after a few minutes.